93

TL;dr - too heavy :-) It's just not a good energy source for something like an aircraft. Nuclear energy is superb for instances where you need continuous output over a long period of time, for example a satellite, which is going to be there for years without maintenance or refuelling. A very small amount of nuclear material in an RTG such as those on ...


72

To a large extent, it wasn't revived because the only realistic use case became obsolete. The USA and USSR were both interested in nuclear-powered long-range bombers. The plan was to have a fleet of bombers loitering in the Arctic so that, if nuclear armageddon was required, they'd already be half-way to their target. They'd also be very hard to destroy as ...


23

Because there was no practical purpose such an aircraft would've served. First and most important, the safety concerns over such an aircraft design would make its use in civil aviation more or less impossible, especially when more and more countries are shying away from nuclear power. This leaves the military. There are quite a few issues with such an ...


16

What if the nuclear powered aircraft crashes? It would be near impossible to design a reactor that could withstand a 500+ mph impact, and you'd have a serious radiation mess to try to clean up. The 'direct cycle' engine, where air is heated directly by the reactor, irradiates the air and leaves a radioactive trail behind it. Both the Soviet TU95LAL and the ...


12

Already great answers here but I`d also like to add... In the 50's it was the atomic age. We thought splitting the atom was the best thing since sliced bread. But that was at a time when we, as humans, had no idea of the long term effects of radiation and radiation poisoning. It really was not until a decade had passed since the dropping of the bombs in ...


7

Along with all the other reasons, there's another - nuclear reactors contain a lot of energy but are not so good at power. An aircraft takes off using 100% throttle. After reaching cruise it throttles back to somewhere around 55 to 70%. During a war mission, they would throttle back up to 100%, basically instantly. Nuclear reactors do not like to throttle. ...


6

The existing answers have already covered the weight, lack of need, and crash safety concerns well, but there is also an additional reason, especially for civilian airliners: hijacking. Securing a nuclear reactor at a power station is feasible because it sits in one place and we can build fences and walls around it with armed security. While submarines and ...


5

I didn't find any direct evidence that Northrop Grumman actually proposed a nuclear-powered Global Hawk. Citation 64 (2 April 2012) in the question doesn't reference a nuclear-powered Global Hawk, only "drones." The pictured Global Hawk was apparently just an illustration. Citation 65 (August 2003?) in the question does reference a nuclear-powered Global ...


2

A nuclear powered aircraft was explored in the US, with the Convair NB36H. The idea was to use the heat from the nuclear reactor instead of burning kerosene to run a gas turbine engine. GE actually built a prototype nuclear powered turbine engine, but it was never used in an aircraft. The NB36H carried a functioning reactor aloft. A lot of shielding had to ...


1

I suppose Nuclear powered airplanes never went from experiment because of the fear one of it falls on your backyard. A Steam-powered airplane went fully airborne, the Besler Steam; the possibility of a Nuclear Reactor driving propellers as in B-36, but through Steam Turbines, seems realistic. A similar concept was used for interplanetary probes, relying on ...


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